Field of the Invention
The present application relates to an electrophotographic photosensitive member, a process cartridge, an electrophotographic apparatus, and an imide compound.
Description of the Related Art
Electrophotographic photosensitive members used in process cartridges and electrophotographic apparatuses typically include on a support member a photosensitive layer containing a charge generating material that is an organic photoconductive material.
The sensitivity of the charge generating material used in the photosensitive layer is being increased. Unfortunately, charge generation is increased with increasing sensitivity, and accordingly, charges become likely to be retained in the photosensitive layer. This is a cause of positive ghost. Positive ghost is a phenomenon that occurs in output images, in which only the portion irradiated with light at the time of the previous rotation of the electrophotographic photosensitive member has a higher density.
In order to suppress such positive ghost, Japanese Patent Laid-Open No. 2014-29480 discloses a technique in which an undercoat layer containing an electron transport material is formed between the support member and the photosensitive layer. This patent document discloses that positive ghost can be suppressed more effectively by adding a polymer of a composition containing the electron transport material, a crosslinking agent and a resin to prevent the structure derived from the electron transport material from being unevenly distributed in the undercoat layer.
According to a study by the present inventors, the electrophotographic photosensitive member of this disclosure is improved in terms of suppression of positive ghost and can provide satisfactory image quality. With growing recent demands for a longer-life electrophotographic photosensitive member and improved image quality, however, suppression of positive ghost at higher level is desirable.